<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>404 - 页面未找到</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        body {
            background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
            min-height: 100vh;
        }

        .container {
            padding: 2rem;
            text-align: center;
            max-width: 800px;
            margin: 0 auto;
        }

        .error-code {
            font-size: 8rem;
            font-weight: bold;
            color: #343a40;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
            animation: float 3s ease-in-out infinite;
        }

        .error-message {
            font-size: 1.5rem;
            color: #6c757d;
            margin: 1rem 0;
        }

        .animation-box {
            width: 200px;
            height: 200px;
            margin: 2rem auto;
            background: url('data:image/svg+xml;utf8,<svg viewBox="0 0 24 24" fill="none" stroke="%236c757d" stroke-width="2"><path d="M12 2v6M12 20v-6"/><path d="M4 8l3 3m10-3l-3 3"/><path d="M18 16l3-3M4 16l-3-3"/><circle cx="12" cy="14" r="4"/></svg>') no-repeat center;
            opacity: 0.8;
        }

        .action-button {
            display: inline-block;
            padding: 0.8rem 2rem;
            background: #007bff;
            color: white;
            text-decoration: none;
            border-radius: 25px;
            transition: transform 0.3s, box-shadow 0.3s;
            margin-top: 1rem;
        }

        .action-button:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0,123,255,0.3);
        }

        @keyframes float {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-20px); }
        }

        @media (max-width: 768px) {
            .error-code {
                font-size: 5rem;
            }
            
            .animation-box {
                width: 150px;
                height: 150px;
            }
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="error-code">404</div>
        <div class="error-message">
            哎呀！您寻找的页面已经消失在数字宇宙中
        </div>
        <div class="animation-box"></div>
        <a href="/" class="action-button">返回首页</a>
    </div>
</body>
</html>